The objective of the invention is to manufacture a detergent composition which can preferably contain up to approximately 90% of surface-active substances and which can be diluted with several times its volume of water to produce a final composition whose viscosity is satisfactory to the user.
In fact, a diluted composition which has a high viscosity is seen by the consumers as being more effective than a composition which has the same concentration of active substances, but a low viscosity. Until now, when the intention was to produce a diluted composition of satisfactory viscosity, the viscosity of the initial concentrated composition was too high to permit its industrial use.
Another objective of the invention is to manufacture a clear detergent composition which, on being diluted with water by the user, gives a stable, viscous, clear composition. The problem to be solved is unusual, because the dilution is performed by the user and, consequently, under conditions which cannot be controlled. Thus, the dilution is done with a variable quantity of water. In particular, this water is tap water and, depending on the locality, it may be harder or softer and may contain different ions. The water temperature can vary and can lie between 0.degree. and 20.degree. C. The flask in which the dilution is carried out can be of any nature and may be a glass or plastic bottle, of a variety of shapes. These dilution conditions are thus completely different from an industrial dilution where the temperature, the quantity and the quality of the dilution water are strictly controlled, as is the stirring and the shape or the nature of the container in which the composition is placed. The compositions according to the invention are preferably employed as a multipurpose liquid, particularly for dishwashing.
French Patent No. 1,462,001 describes detergent compositions containing:
A) water-soluble, lower alkanolamine salts of alkylbenzenesulfonic or alkyltoluenesulfonic acids, in which the alkyl radical contains from 8 to 18 carbon atoms, and
B) nonionic surface agents which are ethoxylated and/or propoxylated ethers of aliphatic alcohols containing at least 8 carbon atoms or of alkylphenols in which the alkyl radical contains from 5 to 18 carbon atoms, and
C) fatty acid amides of mono-, di- or triethanolamine, in which the alkyl radical of the fatty acids contains from 10 to 15 carbon atoms,
and water, and polyphosphates, as well as methyl cellulose and sodium carboxymethyl cellulose.
The alkanolamine salt of alkylbenzenesulfonic and alkyltoluenesulfonic acids is formed on final addition of alkanolamine to the mixture of surface active agents and fatty acid alkanolamide, in the presence of the cellulose derivatives. These salts are thus formed in situ when the various compounds are mixed.
However, these compositions are not intended to be diluted, and so the viscosity of the diluted composition in relation to the viscosity of the concentrated composition is of no concern.
French Patent No. 1,501,661 describes a process for the preparation of a liquid, concentrated detergent composition, which consists in adding a diethanolamine into a surface active agent compound B of the abovementioned type, pouring in the alkylbenzenesulfonic or alkyltoluenesulfonic acid in order to neutralize it, and then adding an ethanolamine fatty acid amide.
According to this patent, the formation of alkyl-benzene- or alkyltoluenesulfonic acid salts is performed by neutralization in situ, that is to say when the various constituents of the detergent composition are being mixed. Furthermore, when the compositions produced are diluted with water to give compositions containing 50-65% of active substances, they form gels.
European Patent Application No. 77,674 describes compositions comprising an amidobetaine, an organic or inorganic salt, water and an anionic surfactant present in quantities of between 0.25 and 15% by weight. The objective described in this document is to produce a thickened aqueous solution by adding to it from 5 to 25% by weight of amidobetaine. The compositions produced may be clear or opaque and may be gels or pastes. These compositions are of relatively low concentration and contain 50 to 70% of water.
European Patent Application No. 88,612 describes liquid detergent compositions capable of being diluted and containing more than 90% by weight of detergent substances containing more than 50% by weight of ethanolamide derived from copra and polyether, that is to say more than 50% of nonionic surface active agents. However, these compositions have a moderate detergent action, because the detergent activity of nonionic surface active agents is weaker than that of anionic surface active agents. Furthermore, these compositions are ternary mixtures which contain no salt to thicken them, because the latter tends to precipitate out.
British Patent No. 1,164,854 describes detergent compositions containing ammonium or amine salts of alkylbenzenesulfonates, ethoxylated alcohols and salts of di- or trivalent metals, for example magnesium sulfate. However, the viscosity of compositions containing 30% of active substances cannot be controlled as a function of the salt concentration and compositions diluted to. 15% of active substances are turbid.
Another objective of the present invention is to provide clear, concentrated, liquid compositions capable of being diluted and containing more than 50% by weight of anionic surface active agents, based on the total quantity of active substances.
French Patent No. 2,156,825 describes aqueous concentrates of alkoxylated alcohol sulfates whose viscosity is lowered by compounds such as lactic, glyceric, tartaric or citric acid, and this enables them to be diluted without gel formation.
French Patent No. 2,304,665 relates to compositions containing an olefinsulfonate to which an acid salt is added to lower the viscosity of the concentrated compositions. This patent relates further to diluted compositions of these mixtures of olefinsulfonate and acid salt. If desired, an alkanolamide may be added to the diluted compositions for the purpose of raising the viscosity of this composition.
Thus, this patent describes a concentrated composition which contains an anionic surface active agent and a salt, or a diluted composition to which a nonionic surface active agent is added.
French Patent No. 2,343,804 describes a composition containing a polyethoxylated nonionic surface active agent and an acid whose role is to increase the detergency of the composition.
U.S. Pat. No. 4,092,273 describes a detergent composition which contains an agent which counteracts gel formation at low temperature. This agent is a diacid salt.
French Patent No. 2,106,927 describes a descaling composition containing a detergent, an acid and a thickener based on cellulose ether.